Lamp-socket.



W. H. KEMPTON.

LAMP SOCKET, APPLICATION FILED 121313.13, 1909.

Patented Aug. 24, 1909.

'WILLARD H. KEHPTON, OF HB'IFORID, CONNECTICUT, ASSIGNOR T0 THE JOHNS-PRATT COMPANY,

UNITED sTATus PATENT ernten.

0F HARTFORD, CONNECTICUT, A CORPORATION 0F CONNECTICUT.

LAMP-SGCKET Specicatiou or Letters Patent.

Application filed February 13, 1909. Serial No. 477,551.

To all whom it may concern:

Be it known that l, VILLARD H. Kmar- ToN, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have. invented a new and useful Lamp-Socket, of which the following is a specification.

This invention relates to sockets for incandescent lamps, Aand more particularly to those sockets which are provided for lamps that are to be used in a series circuit.' Sockets of this class are necessarily constructed so that they will act automatically and close the circuit,'in order to permit a'continuance of the ow of current therethrough, whenever one or more lamps burn out, or become destroyed, or are removed lfrom the sockets for any purpose.

The object of the present invention is to provide a simple, and cheap socket of this A nature which will surely and efficiently close the circuit so that the current flow will be maintained whenever a lamp burns out, or becomes broken, or is removed, without damage to any of the permanent conducting arts, and which is so constructed that it can be easily but quickly renewed and re' stored to normal condition whenever a new lam is placed therein.

Figure 1 of the accompanying drawings shows a central section of the body of a socket which embodies this invention, and also the-parts which are assembled therein when the socket is in operative condition. Fig. 2 shows a similarview of the same socket with the parts in the positions occupied when a lamp is being inserted therein. Fig. 3 shows a similar view of the-parts with the lamp base screwed all the way into the socket, and Fig. 4 shows a detail of 'a moditied form of one of the parts that may be used in the linterior of this socket.

The body 1 of the socket shown, is made of weatherproof insulating material, such as porcelain or a molded waterproof insulating compound. If the body of the socket, as 1s illustrated in the drawing, is formed of a molded insulating compound, a metallic threaded shell 2, preferably brass, is molded in the interior so as to line the side wall of the recess and provide the outer terminal, and a .plate 3 with a centrally projectin stud 4, also brass, is molded in the end wal of the recessin` the body to provide the central terminal. Lead wires 5 and t3, may be embedded in the end of the lsocket when it is formed, ,one of the leads being connected .with the central 'terminal plate or stud, and

the other being connected with the shell or outer terminal, to provide the usual conneotions'between the circuit wires and the lamp terminals of the socket. A conductor 7, preferably made of brass, in the form of a cup with a threaded side wall and a per- 'foi-ated end wall, is located inthe recess and electrically connectedf'with the shell near the inner end thereof. Loose inside of the cup is a disk 8, that has a tubular stem 9 which extends through the opening in the end of the cup. The stud that projects from the central terminal plate in the body, at the end of thev recess, extends through this stem of the loose conductor disk. Coiled around the stud and thrusting against the central terminal in the body, and the loose disk in the cup, is a spiral spring 10. When there is nothing beneath the tubular stem of the loose disk to hold it up, this spring presses the disk against the end of the cup and completes a circuit comprising the central contact plate, spring, loose disk, cup and shelll or outer contact, from one lead wire to the other so that a How of current can be maintained through an empty socket.

The ring 11, of insulating material, either porcelain ormolded insulating compound, bearing a metallic plate 12, is placed inthe socket between the cup and the lamp oase 13. This ring can be of such size that it may be simply thrust upinto the socket, as is the ring 11, shown in Figs. 2 and 3, or, it may have its exterior threaded, as is the ring 14, shown in Fig. 4, so that it may be screwed up into the shell. It is preferred to arrange the spring 15 between the plate carried by the ring and the cap 16, which is designed4 to engage the central contact 17 on the lamp base. Between the bottom of the cup and the plate carried by the ring, a thin washer 18 ofinsulating material, is placed. This washer may be made of paper, but it is preferably made of a substance, rich in carbon, such as bitumen, although of course it could be made of thin mica, having one or more perforations therethrough.

lt there is no lamp in the socket, the-loose disk is thrust by the spring above it, or it drops by gravity if there is no spring against the bottom of the cup, which is in metallic engagement with the lining, and the circuit from one lead wire to the` other is closed through these parts. lVhen a lamp base is screwed into the socket with a ring and insulating washer placed above it, the `spring below the plate carried by the ring thrusts the pla te and ring upwardly, and holds them up with the insulating washer close against the underside of the cup and forces the cap down against the central contact on the lamp base. "Vith the parts in this position, the engagement ot' the end of the stem with the cap holds the loosedisk up and out of engagement with the bottom of the cup, so that the circuit is opened between the disk and cup, but is closed through the stem and central contact of the lamp base, the shell on the base of the lamp engaging the shell in the socket and completing the circuit in the usual manner. Vhenever a lamp held by one of these sockets burns out, or becomes broken, or has its filament ruptured from any cause, there is a momentary concentra-- tion of electrical pressure between the bottom of the cup and the plate carried by the ring, which, if the washer separating t-hese parts is of paper, is sufficient to puncture the paper and cause the insulation to break down and establish a circuit between the plate carried -by the ring, which is in electrical connection with the central terminal, and the bottom of the cup, which is in electrical connection with the outer terminal. If the disk is of mica with perforations, the circuit is completed through the perforations in the mica, but if the preferred form of insulating washer is used, that is the washer is made of a substance rich in carbon, such as bitumen, which vunder normal conditions pro-v vides a complete electrical insulation of the parts, but when subjected to heat and abnormal electrical pressure, becomes carbonized and forms a good conductor, the current will flow from one lead to the other through the washer and the metallic parts each side of it. When the lamp is removed,

the circuit which is then opened through the lamp, is immediately completed by the loose disk so that the other lights on the circuit are not interfered with. All that it is necessary to do, in order to restore the parts to normal condition, is when another lamp is screwed into the socket to substitute a new insulating washer between the ring and the cup for the one ruptured, which washers are very light, small and cheap, and can be quickly and easily supplied.

The invention claimed is:

l. Alamp socket having a recessed bodyy of insulating material with a closed upper end, a shell located in the body, a central conducting contact at the end of the recess i in the body, a circuit wire connected with the shell, alcircuit wire connected with lthe central contact, a conductor removably 1ocated in the recess through the bottom of the socket* and connected with the shell, and a conductor located in the recess and connected with the central contact, one of said conductors being movable whereby they are engaged when there is no lamp in the socket, but are disengaged when there is a lamp in the socket'.

2. A lamp socket having a recessed body of insulating material with a closed upper end, a conductingshell located therein, a central conducting contact located at the end of the recess, a circuit wire connected with the shell, a circuit -wire connected with the central contact, a conductor removably located in the recess through the bottom of the socket and connected with the shell, a conductor loosely located in the recess and connected with the central Contact, and a spring arranged to force the conductor connected with the central contact against the conductor connected vwith the shell.

3. A lamp socket having a recessed body of insulating material with a vclosed upper end, a conducting shell arranged within the body, a conducting contact located centrally of the end of the shell, a circuit wire connected with thel shell, a circuit wire connected with the central contact, a conductor removably located in the' recess through the bottom of the socket and connected with the shell, a 'conducting plate arranged in and insulated from the shell, and connected with the central contact, and an insulating washer arranged between said conducting plate and the conductor connected with the shell.

4. A lamp socket having a recessed body of insulating material, a conducting shell located in the body, a contact located cen- `trally at the end of the recess in the'body, a

conductor located in the recess and connected with the shell, a conductor loosely located in the recess, said conductor being connected with the central contact and adapted to be engaged with the conductor connected with the shell, a conducting plate arranged and insulated from the shell, and an insulating washer arranged between the said conducting plate andthe conductor connected with the shell.

5. A lamp socket having a recessed body of insulating material, a conducting shell located in the body, a conductor located centrally of the body, a conductor located in the recess and connected with the shell, a

conductor loosely arranged in the recess,

said conductor being connected with the central contact and adapted to be engaged with the conductor connected with the shell, a conducting plate arranged in and insulated from the shell, an insulating washer arranged between the said plate and theconductor connected with the shell, a spring arranged between the end of the recess and the movable conductor connected with the central contact, and a spring arranged to nected with the shell, when a lamp 'base is v turned ull way into the shell.

a recessed body 6. A lamp socket havin of insulating material, a t readed conduct- .ing shell located in the body, a Contact plate located at" the end of the recess in the body, a stud projecting from said plate, a disk with a tubular stem movable on 'said stud, a cup screwed into thesshell, a ring of insulating material bearing a contact yplate and an insulating disk arranged below the cup, and a spring and cap arranged to thrust the plate, rlng and the insulating disk upwardly against the bottom of the cup when a lamp base is screwed full way into the socket.

7. A lamp socket having a recessed body of insulating material, a shell of conducting material located in the body, a central conducting contact, a removable conductor eX- tending across the recess and connected with the shell, and a conductor electrically connected with the central contact and movable in the recess in the socket above the removable conductor, said movable conductor being adapted to engage the conductor connected with the shell when there is no lamp in the socket, and to be moved out of engagement therewith when a lamp base is turned full Way into the shell.

8. A lamp socket having a recessed body of insulating material, a shell of conducting material located in the-socket, a central contact, a conductor extending across the recess and connectedwith the shell, a conductor connected with the central contact, and an insulating washer arranged between said latter conductor and theconductor connected with the shell.

9. A lamp socket having a shell of conducting material, a yielding central conducting contact, a conductor removably inserted into the socket and connected with the shell above the lower end of the central contact, a conduct-ing plate arranged below'said conductor and yieldingly connected with the .central contact, and a piece of carbonizable material arranged between vsaid plate and said conductor that is connected with the 5 shell. y

WILLARD H. KEMPTON.

Witnesses:

H. R. WILLIAMS, JosEPHINE M. STREMPFER. 

